It crash kernel when device was removed while it was streaming.
That is because we removed driver and frontend thread was still
running. Use new callback which allows I2C driver removal just
after frontend is unregistered.

V2: fixed by reported by Daniel
Reported-by: Daniel Glöckner <daniel-gl@gmx.net>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>